Clinical relevance of the effects of individual music therapy: effect sizes and number needed to treata

Effect size, d

Risk difference, %

Number needed to treat

Montgomery–Åsberg Depression Rating Scale

0.65

Hospital Anxiety and Depression Scale – Anxiety

0.49

Global Assessment of Functioning

0.62

Response

24

4

a All analyses intention-to-treat. Effect sizes were calculated as the difference in change at 3 months divided by the pooled standard deviation at baseline (Table 1), with signs reversed where applicable so that a positive effect size indicates a difference in favour of music therapy. Risk difference and number needed to treat are based on the numbers with no response at 3 months (Table 3).